Pole analysis for the $D^{\ast }\bar{K}$-$D\overline{K^{\ast }}$ coupled-channel system

Abstract

By solving the Lippmann-Schwinger equation, possible hadronic molecules in the $D^{\ast }\bar{K}$-$D{\bar{K}}^{\ast }$ coupled-channel system are investigated with the one-meson exchange potentials, where both vector and pseudoscalar mesons are considered as exchange particles. We find an S-wave virtual state with mass $M=2487$ MeV, and a resonance with $M=2759$ and width $\hat{I}“=18$ MeV. In the $D^{\ast }\bar{K}$ invariant mass distribution, the virtual state appears as a cusp at the $D^{\ast }\bar{K}$ threshold, while the resonance potentially manifests as a dip. In particular, we take into account the $D\bar{K}\ddot{I}€$ three-body dynamics due to the on-shell pion exchange and the finite decay width for ${\bar{K}}^{\ast }$.

22 pages, 2 figures. Version to appear in Phys. Lett. B